Selected Internet Protocol (IP) traffic offload (SIPTO) is a method to offload traffic from a wireless communication system operator's core network (CN) to a defined IP network that is close to a point of attachment to the access point of a wireless transmit receive unit (WTRU). The traffic may be offloaded to another path based on the geographical (or topological in terms of IP) location of a WTRU. Thus, a goal of SIPTO is to offload some of the IP traffic from traversing nodes at the CN. Local IP Access (LIPA) is a method for providing access for IP-capable WTRUs that are connected via an H(e)NB (for example, using H(e)NB radio access) to other IP capable entities in the same residential or enterprise IP network. Traffic for LIPA typically does not traverse the mobile operator's network except for accessing particular information at the H(e)NB. A packet data network (PDN) connection established for the WTRU may be used for SIPTO and/or LIPA without the WTRU being aware of the use of SIPTO and/or LIPA.
In a wireless network capable of providing SIPTO or LIPA services, a Local Gateway (L-GW) may be located apart from an H(e)NB. Accordingly, a WTRU may be capable of moving between H(e)NBs while still maintaining a connection to one L-GW. The WTRU may therefore be able to continue to receive SIPTO or LIPA services while moving between H(e)NBs. Local H(e)NB Networks (LHNs) are networks that include one or more H(e)NBs that are in communication with a given L-GW. A LHN may also include H(e)NBs that belong to more than one Closed Subscriber Group (CSG). Based on the separation of the L-GW from the H(e)NBs and the potential handover of the WTRU between more than one H(e)NB, methods are needed to support WTRU mobility between H(e)NBs and to support SIPTO and/or LIPA services during WTRU mobility.